By way of background, many miles of existing highways comprise asphalt-based materials in combination with various aggregates such as gravel, crushed stone, and sand. Numerous additional miles are built each year in which asphalt serves as the main component. The continued widespread use of such material, however, depends substantially upon cost, durability of the surface, and the frequency and nature of required preventative maintenance in response to constant weather and vehicular-induced damage. Fiber reinforcement and laydown procedures are very important with respect to such cost and durability factors.
For example, when repair or resurfacing of asphalt or asphalt-based road surface is carried out, hot fiber-containing liquified asphalt or asphalt fiber-reinforced emulsions are applied in one form or another as filler, as a waterproof underlayer between old and proposed new paving surfaces, and an external surfacing material. For each purpose, however, the amount and fineness of aggregate, the nature and amount of curing and thickening agents, and the concentration of reinforcing fiber and various other additives can vary widely, depending upon desired characteristics.
Because of the relative expense and the general importance of fiber reinforcement generally, and because of the difficulty in mixing light fiber components evenly into viscous compositions of the above type without clumping or clogging, and because of the substantial dependence of road paving applications on ambient temperature or weather, it is found useful to set up centrally located asphalt processing plants such as drum mixing plants, of a transient or mobile type which are capable of providing substantial amounts of various mixtures of asphalt with one or more of aggregate (including sand), reclaimed materials, fiber, filler such as curing agents, and recirculated bag fines, etc., under proper condition for delivery and lay down.
It is an object of the present invention to obtain an easily assembled device for efficiently preparing premix compositions comprising a viscous composition component and light weight reinforcing fiber component for introduction into a suitable receptacle.
It is a further object to reduce fiber and other fines loss and to minimize potential heat damage to fiber inherent in asphalt drum mix operations through use of an efficient premixing device.